<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Bootstrap Examples</title>
    <meta name="description" content="">
    <meta name="keywords" content="">
    <!-- 新 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap.min.css">
    <!-- 可选的Bootstrap主题文件（一般不用引入） -->
    <link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap-theme.min.css">
    <!-- jQuery文件。务必在bootstrap.min.js 之前引入 -->
    <script src="//cdn.bootcss.com/jquery/1.11.3/jquery.min.js"></script>
    <!-- 最新的 Bootstrap 核心 JavaScript 文件 -->
    <script src="//cdn.bootcss.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
</head>

<body>
    <p class="bg-primary">该段落使用了类 "bg-primary"。</p>
    <button class="btn-primary"></button>
    <form action="" method="POST" role="form">
        <legend>Form title</legend>
        <div class="form-group">
            <label for="">label</label>
            <input type="text" class="form-control" id="" placeholder="Input field">
        </div>
        <button type="submit" class="btn btn-primary">Submit</button>
    </form>
</body>

</html>
